A case of metachronous oligo-hepatic and peritoneal metastases of pancreatic cancer with a favorable outcome after conversion surgery combined with perioperative sequential chemotherapy.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies, and the prognosis for its recurrence after surgery is very poor. Here, we report a case of metachronous oligo-hepatic and peritoneal metastases in a patient who survived without recurrence for 3 years after conversion surgery combined with perioperative sequential chemotherapy using gemcitabine plus nab-paclitaxel (GnP) and modified FOLFIRINOX (mFOLFIRINOX). The patient was a 70-year-old man with pancreatic ductal carcinoma, classified as cT3N0M0, cStage IIA, who underwent a distal pancreatosplenectomy. At 1 year and 4 months later, two liver metastases and one peritoneal metastasis were detected. A systemic 9-month course of chemotherapy was administered with GnP and mFOLFIRINOX as the first- and second-line chemotherapeutic agents, respectively. The two liver metastases were judged as showing a partial response, but one dissemination was considered stable disease. After receiving informed consent from the patient, we performed resection of the disseminated tumor and lateral segmentectomy of the liver. Adjuvant chemotherapy using mFOLFIRINOX and GnP was administered for 10 months. The patient has now been alive for 5 years and 6 months after the initial pancreatosplenectomy, and 3 years and 3 months after the conversion surgery, without subsequent tumor recurrence. Thus, a multidisciplinary treatment approach including surgery and perioperative sequential chemotherapy using GnP and mFOLFIRINOX may be beneficial for treating metachronous oligo-hepatic and peritoneal metastases, depending on the patient's condition.